test_runner: Migrate MockWebAudioDevice to our Chromium C++ style.

test_runner: Migrate MockWebAudioDevice to our Chromium C++ style.

Changes:
1) Run clang-format through source and header files.
2) Fix data member variables to use unix_hacker_ style.
3) Rename file name to mock_web_audio_device.

BUG=331299
TEST=content_unittests, content_shell. No functional changes
TBR=dpranke@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275421

[tfarina, 2014-06-06 07:15:14]

TBRing...(please, rubber stamp).

thanks,

[tfarina, 2014-06-06 07:15:16]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-06-06 07:17:45]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tfarina@chromium.org/317253004/20001

[jochen (gone - plz use gerrit), 2014-06-06 07:29:56]

lgtm

[commit-bot: I haz the power, 2014-06-06 11:51:13]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  linux_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/bu...)

[commit-bot: I haz the power, 2014-06-06 13:21:34]

Change committed as 275421